TWSBI Diamond 580 Fountain Pen Overview

TWSBI Diamond 580 Fountain Pen Review

Back in 2009, TWSBI disrupted the fountain pen market with the Diamond 530 fountain pen. Over 10 years and several design upgrades later, the Diamond 580 continues the company's mission to provide a quality, affordable fountain pen that helps people slow down and appreciate the craft of writing. In this article, we will look at all the transparent details of this revolutionary pen.

When most pen manufacturers were looking to service a luxury market, TWSBI reached out to fountain pen enthusiasts on the internet to help design a traditional fountain pen that modern society can appreciate. TWSBI developed the original Diamond 530 around these core principles: that pen should be functional, aesthetically pleasing, affordable, and teach the user how to enjoy a slower-paced lifestyle.

Unique Features of the TWSBI Diamond 580 Fountain Pen

The first noticeable feature of this pen is the totally clear, diamond-faceted barrel. Not only does it allow an unobstructed view into the workings of the piston mechanism, but the transparency also provides an aesthetically pleasing view of your ink.

The Diamond 580 has a generous size and balance in-hand. The barrel and rounded piston-knob are separated by a polished chrome trim ring. The concave grip section ends with a chrome band just before the nib and feed.

The clear cap gently tapers from the wide ring at the opening to the clip and finial at the top. The wedding-ring style band has the TWSBI logo, the words "Diamond 580," and "Taiwan" laser-etched into the polished surface. The round jewel atop the cap displays the red TWSBI insignia. An inner cap sleeve helps the nib stay freshly-inked while capped.

In the Diamond 580AL model, TWSBI upgrades the front grip section and the piston mechanism with aluminum metal for a more substantial look and feel.

Comparing the TWSBI Diamond 580 with Other Piston-Fill Pens

Here is the TWSBI Diamond 580 compared with other piston-fill, demonstrator-type pens, including the Pelikan Classic M205, Penbbs 309, Narwhal, and Noodler's Konrad.

TWSBI Diamond 580 Fountain Pen Overview
*Measurement* Penbbs 309 Noodler's Konrad Diamond 580 Narwhal Piston-Fill Pelikan M200

Length Closed/Capped

5.70 in. / 145mm

5.1 in. / 129mm

5.59 in. / 142mm

5.77 in. / 146.5 mm

5.00 in. / 126mm

Length Uncapped


5.00 in. / 126mm

5.12 in. / 130mm

5.24 in. / 133 mm

4.80 in. / 121mm

Length Cap Posted


5.70 in. / 145mm

Cannot be posted

Cannot be posted

5.90 in. / 149mm

Barrel Max Diameter

0.47 in. / 12mm

0.47 in. / 12mm

0.52 in. / 13.3mm

0.53 in. / 13.5 mm

0.47 in. / 12mm

Section Grip Diameter


0.40 in. / 10mm

0.4 in. / 10mm

0.43 in. / 11 mm

0.4 in. / 9mm

Pen Weight

0.70 oz. / 20g

0.5 oz. / 15g

1oz / 28g

0.70 oz. / 20g

0.5 oz. / 14g

Nib Options and Writing Experience with the TWSBI Diamond 580

To accommodate most handwriting styles, the Diamond 580 features number 5 stainless steel nibs available in extra-fine, fine, medium, broad and 1.1mm stub tip sizes. You can swap with a replacement TWSBI Diamond 580 nib unit by unscrewing and replacing the section. The replacement 580 nib is also compatible with the 540 and 530 pen models.

TWSBI Diamond 580 Fountain Pen Overview

Filling the TWSBI Diamond 580 Fountain Pen

Filling the piston mechanism follows the same procedure as any internal piston-fill fountain pen. To take filling to the next level, TWSBI designed the Diamond 50 ink bottle - the perfect companion for easy, mess-free filling.

Writing with the Diamond 580 is a pleasurable experience to behold. The crystal clear barrel shows ink sloshing around as the nib dances on the page. The cap is not meant to be posted on the back of the pen. The barrel's length and balanced design have a comfortable feel, even during long writing sessions. And you'll be writing a long time with this pen between fill-ups, as the barrel reservoir holds nearly 2ml of ink.

TWSBI Diamond 580 Fountain Pen Overview

Special Editions

Pictured above is the TWSBI Diamond 580ALR in Prussian Blue. This is a special edition color for June of 2020. The "R" in 580ALR signifies the concentric rings engraved into the grip section and cap finial to distinguish this model from the aluminum 580AL.

Pen collectors are eager to add new, special edition TWSBI Diamond 580 colors. New editions are released periodically throughout the year and are available for a limited time. So, be sure to sign up for the Goldspot e-mail newsletter to get all our updates on special and limited edition pens.

The Diamond fountain pen is a meticulously-designed experience from the packaging to the easy-to-follow instructions. Beyond the literal transparency of the diamond-faceted barrel, the TWSBI brand adopts transparency as its core value. In TWSBI's own words, they "felt it was important to allow the user to disassemble and reassemble the pen and completely experience the traditional aspects of owning and using a fountain pen."

To give the writer more ownership of their writing instrument, TWSBI provides a wrench and silicone grease with instructions on how to properly disassemble and reassemble the fountain pen when it might require thorough cleaning or maintenance.

Do you own a TWSBI Diamond 580? Looking to get one in the near future? Let us know in the comments below. Thanks for checking out this pen review

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